An update on that sleek, but unknown Nvidia Tablet we showed you yesterday. As widely expected, it's actually a prototype Tegra-based device built by an ODM for Nvidia to shop around to wireless carriers worldwide. Here's what we may know:

Engadget says a credible tipster suggests it currently runs Windows CE and has a resistive touchscreen, but Android and capacitive upgrades (and different screen sizes) are likely. A March 2010 arrival is rumored, as is T-Mobile's involvement. Interesting, but definitely still an undercooked rumor at this point. We'll let you know when we hear more. [Engadget]